A buoyancy adjusting device for an underwater device is described the device comprising: a tube having first and second ends; a resilient mechanism located at the first end of the tube and extending towards the second end of the tube; an opening near the second end of the tube; a catch at the second end of the tube; 5 and at least one block insertable into from the first end of the tube to adjust the buoyancy.

A buoyancy adjusting device for an underwater device is described the device comprising: a tube having first and second ends; a resilient mechanism located at the first end of the tube and extending towards the second end of the tube; an opening near the second end of the tube; a catch at the second end of the tube; 5 and at least one block insertable into from the first end of the tube to adjust the buoyancy.

An unloading type sinking rescue device of a subsea mining vehicle and a use method thereof are provided. The unloading type sinking rescue device includes an assembly support, an unloading system, an ejection system and a control system. The assembly support is box-shaped, fixed to a subsea mining vehicle, and provided with a plurality of enclosed cavities. The unloading system includes a counterweight, a counterweight cable, a counterweight fixing bracket and a counterweight recovery cavity. The ejection system includes an anchor, an ejection cavity, an anchor cable, an anchor recovery shaft, a pulley, a spring and a boosting device. The control system controls the operation of the unloading system and the ejection system. The use method includes: (1) unloading; (2) ejection; (3) recovery of a part of counterweights; (4) recovery of the anchor; and (5) recovery of remaining counterweights.

A submersible node and a method and system for using the node to acquire data, including seismic data is disclosed. The node incorporates a buoyancy system to provide propulsion for the node between respective landed locations by varying the buoyancy between positive and negative. A first acoustic positioning system is used to facilitate positioning of a node when landing and a second acoustic positioning system is used to facilitate a node transiting between respective target landed locations.

A submersible node and a method and system for using the node to acquire data, including seismic data is disclosed. The node incorporates a buoyancy system to provide propulsion for the node between respective landed locations by varying the buoyancy between positive and negative. A first acoustic positioning system is used to facilitate positioning of a node when landing and a second acoustic positioning system is used to facilitate a node transiting between respective target landed locations.

A submersible node and a method and system for using the node to acquire data, including seismic data is disclosed. The node incorporates a buoyancy system to provide propulsion for the node between respective landed locations by varying the buoyancy between positive and negative. A first acoustic positioning system is used to facilitate positioning of a node when landing and a second acoustic positioning system is used to facilitate a node transiting between respective target landed locations.

A submersible node and a method and system for using the node to acquire data, including seismic data is disclosed. The node incorporates a buoyancy system to provide propulsion for the node between respective landed locations by varying the buoyancy between positive and negative. A first acoustic positioning system is used to facilitate positioning of a node when landing and a second acoustic positioning system is used to facilitate a node transiting between respective target landed locations.

An underwater body having a movable component which can be moved into a retracted position and, as a result, increases the volume of the underwater body. In addition, a method is disclosed for operating such an underwater body. An expansion means conducts a fluid into a hollow space. The hollow space is operatively connected to the movable component. When the fluid is conducted into the hollow space, the movable component is moved into the extended position relative to the shell of the underwater body. The fluid in the hollow space hardens. The hardened fluid in the hollow space holds the movable component in the extended position.

An underwater body having a movable component which can be moved into a retracted position and, as a result, increases the volume of the underwater body. In addition, a method is disclosed for operating such an underwater body. An expansion means conducts a fluid into a hollow space. The hollow space is operatively connected to the movable component. When the fluid is conducted into the hollow space, the movable component is moved into the extended position relative to the shell of the underwater body. The fluid in the hollow space hardens. The hardened fluid in the hollow space holds the movable component in the extended position.

A submersible node and a method and system for using the node to acquire data, including seismic data is disclosed. The node incorporates a buoyancy system to provide propulsion for the node between respective landed locations by varying the buoyancy between positive and negative. A first acoustic positioning system is used to facilitate positioning of a node when landing and a second acoustic positioning system is used to facilitate a node transiting between respective target landed locations.